I have the Game Pass for Microsoft PC.
At the moment I press download in the Microsoft store the download ends instantly and the game appears downloaded but with an icon of an arrow down. When I try to start the game, it redirects me to the download section of the store.
Mine simply doesn’t launch…!!!
Could you try to click that icon. You will head into the download screen where you can click the start download / install button. You can also pause downloads there. Sometimes I have to open the installed version in store first and then click that same icon to get the download of an updated version.